Slug-trimming knives for typographical line-casting machines



June 23, 1931. c. MUEHLEISEN `1,811,145

SLUG TRIMMING KNIVES FOR TYPOGRAPHICL LINE CASTING MACHINES Filed March 5j 1930 lz'yf fyi y a d Z Patented June 23, 1931 UNITED STATES lPATENT OFFICE CARL MUEHLEISE'N, OF BERLIN, GERMANY, ASSIGNOR TO MERGENTHALER LINOTYPE COMPANY, ,OF BROOKLYN, NEW YORK SLUG-TRIMMING- KNIVES FOR TYIVPOGRAPHICAL LINE-CASTING MACHINES Application filed March 5, 1930, Serial No. 433,217, and in Germany `March 8, 1929.

In matrix composing and line-casting machines, the cast slug, when ejected from the mold, is pushed between knives, by which they are trimmed on their flatsides. It sometimes happens that, even with knives set quite parallel and ground perfectly true, the slugs trimmed by them exhibit slight differences in thickness, especially between long and short slugs. These differences are in all probability due to the irregular contraction of the slugs when cooling before and during the trimming operation.

In particular, short slugs are slightly thinner at the ends thereof which are trimmed by the centre part of knives which are adapted also for trimming long slugs. The object of the invention is to overcome this difficulty. For this purpose, one of the two knives be tween which the slugs are pushed when ejected, is so constructed that its cutting edge can be set slightly out of parallelism with the cutting edge of the other knife, the said knife being capable of bending into a slightly hollow or concave form, in order to ensure that short slugs shall be of the same lthickness throughout their whole length.

It might be assumed that with such a con-v struction, the long slugs would no longer be true, but rather thicker at the centre than at the ends. This, as a matter of fact, does not happen, owing t0 the fact that as a result of the manner in which the casting metal is injected, the latter is hotter at the centre, and consequently long slugs contract more at the centre than at the ends. Thus long slugs are also trimmed accurately, notwithstanding the fact that the knives are set a little further apart at the centre. Either of the two knives, preferably that which is usually the righthand one, or both knives, may be set concave in the manner indicated.

The invention is hereinafter described with reference to the accompanying drawings,

which illustrate different constructional forms of the invention. In the said drawings Figure 1 is a front elevation of the knife, the edge of which is to be concaved;

Figure 2 is a side elevation thereof; Figure 3 is a front elevation of a knife according to a further constructional formv of the invention;

Figure t is a sectional View on the line 4 4 of gure 3; Y

Figure 5 is a view similar to Figure 3 of a knife according to a third constructimal` form of the invention, and

Figure 6 is a side elevation thereof.

In the constructional form of the invention illustrated in Fioures l and 2, the improved knife is made in one piece, and is provided with a long slot c, by which the central portion of the knife is divided into two sections a and the ends .of the knife beyond the slot being united in one 'solid body, so that in` the centre the weaker section?) can yield towards the section a. At about the centre of the slot c, a screw Z is provided, which passes freely through an opening in the knife-section b and is screwed into a threaded hole in the section ci. The head of this screw is located in a recess in the section b, and does not project beyond the cutting surface. By tightening the screw d the knife section Z) can be brought a little closer to the section a at the centre, the knife edge thus being concaved in the direction of its length. Lock a theknife a b. The slugs g to be` trimmed, may be of the short lengthy, as indicated in full lines in Figure 1, or of the longer length indicated by full and dotted lines in that figure.

In the constructional form according to C Figures 3 and 4, the knife it, as in the previously described construction, is made in one piece, but here it is provided with a groove z', extending throughout the whole length of the knife, which allows the thinner portion h1 bearing the cutting edge, to be concaved. A screw 7c, which traverses the centre of the knife through a hole in the section h1, and is screwed into the section 7L, serves to bring about the concave formation of the knife. Here too, the head of the screw 76, is located in a recess, and a lock-nut 71:1 serves to secure it in adjusted position.

In the constructional form illustrated in Figures 5 and G, the knife is formed in two separate portions. The main or body portion m, is rebated for receiving the knife portion n. rl`he portion n is provided With three supporting' projections 0, 01, 02, the centre one 0L being slightly shalloWer than the outer l ones. The projections are traversed by lixing screws j), and as a result of the projection 01 being shalloiver than the others 0, 02, the knife portion n is concaved midway of its length.

By reason of the foregoing provisions, any of these illustrated constructions of knife can be concaved at its cutting edge when desired, or adjusted parallelly to the companion knife; or, in the construction represented in Figures l and 2, the cutting edge may be bent even into convex form for example for grind ing purposes. With the construction illustrated in Figures l and 2, Vit has been found practicable for the knife to be deflected to the extent of one thousandth part of an inch.

Having described my invention, I declare that what l claim and desire to secure by Letters Patent is l. A slug-trimming knife for typographical line-casting machines, having a resilientV cutting-edge and means for deflecting said edge to a curvilinear form.

2. A slug-trimming knife for typographical line-casting machines, having a resilient cutting-edge and means for defiecting said edge to a concave form.

slug-trimming knife for typographical line-casting machines comprising a body portion and a. cutting-edge portion, the said portions being separated by a gap, and means adapted to deiect the cutting-edge portion relatively to the gap.

Ll. A slug-trimming knife for typographical line-casting machines comprising a body portion and a cutting-edge portion, the said portions being separated by agap, means adapted to deflect the cutting-edge portion relatively to the gap, and clamping means adapted to secure said portion in its deflected position.

5. A slug-trimming knife for typographical line-casting machines comprising a body portion and a cutting-edge portion, the said portions being separated by a gap, a projection on the cutting-edge portion extending into the gap, and a clamping device penetrating said projection adapted to bed the foot of the projection against the body portion of the knife.

6. A slug trimming knife for typographical line-casting machines comprising a body portion and a cutting-edge portion separate from the body portion, a plurality of projections on the cutting edge portion of which an CARL MUEHLEISEN.

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